American iguanas poison themselves with ant poison to survive.

Iguanas eat dead ants, receive a small dose of their poison and prepare their immunity for possible poisoning. This was proved by the experiment of biologists. They divided the lizards into two groups. For one to three weeks they were fed ants, and then they were allowed to sting. The second only suffered from bites. It turned out that in the blood of iguanas from the first group, the concentration of basophils increased and substances were produced that bind the poison molecules and prevent it from affecting the body. There were no such changes in the second group.